440 Bulletin American Museum of Natural History. [VoL XIX, 



of the length, and they are permitted the notochord to pass 

 continuously through them. In the abdominal region there 

 appear to be no neural spines. These are first seen as low 

 and rather broad plates just over the origin of the anal fin. 

 They soon become considerably higher and quite slender, but 

 expanding somewhat toward their distal ends. The haemal 

 arches are well developed, the spines of many of the anterior 

 ones being expanded at their distal extremities. Only the 

 merest traces of a few ribs are seen in the specimens. 



The rays of the dorsal and anal fins are slender, and there 

 are, on an average, two and one third interneurals and inter- 

 hsemals for each vertebra. 



The cleithrum is preserved in its natural position. It is 

 sigmoid in form, and is pointed at both the upper and the 

 lower end. The substance of the pectoral fins is wanting, but 

 there is present what appears to be the imprint of one on the 

 matrix. 



So far as preserved, the head resembles that of Anguilla. 

 The hinder portion of the lower jaw is present, articulated to 

 the quadrate. It is not certain that any part of the palato- 

 pterygoid arch is seen. A strongly developed hyoid arch is 

 present, and to each side are attached at least 15 branchios- 

 tegal rays. These are long and slender, some of the upper- 

 most ones being broadened at their hinder ends and turned 

 upward. The opercular bone is probably represented by a 

 flake of bone. 



Both the specimens appear to have been enveloped in a 

 fine matrix without any part having been disturbed. The 

 lower outline of the body is distinctly marked by a brown 

 stain. This stain and minute patches of similar stain on the 

 sides of the abdominal region may indicate the existence of 

 scales, but of these there is no other evidence. There are no 

 traces of enlarged scales along the sides of the body, such as 

 are found in A. qtiadripinnis . 



This eel resembles rather closely Davis's Urenchelys hakel- 

 ensis, and at first it was regarded as such. A closer study 

 has, however, made it certain that the two are distinct species. 

 In U. hakelemis the dorsal fin probably came forward to the 



